From 1971 to 1981, at the Remehue Res. Sta. (INIA), Osorno, three methods of improving natural pastu res were tested:
1. Preparing a seed bed and sowing a mixture;
2. Drilling the seed directly into the pasture; and
3. Fertilizing the natural pasture.
Two plots, of 3 ha each, were assigned to each treatment; each plot was subdivided in 5 Iots. From the fifth season on, a tester treatment (natural pasture without fertilizers) was added. Steers (from 6-7 to 18-19 months of age) grazed the pastures year-round. Fertilization was the same for alI treatments. From the sixth season, stocking rate was raised from 3 to 4 steers/ha, in the improved pastures, and reduced from 3 to 2 steers/ha, in the tester. During the first year, uve weight output (kg/ha) was 390, in the fertilized natural pasture, and 480 in the other two fertilized treatments. Such yields increased through the years, reaching about 600 kg/ ha in the third season, for the three treatments. There on, these yields were alike, with values aboye 900 kg/ha during 1980-81. The zero fertilizer treatment increased from 322 to 372 kg/ha. Botanical composition changed in the natural fertilized pasture, toward a high percentage of desirable species. It was concluded that, with fertilizer and proper management, a natural pasture can yield over 900 kg/ha of live weight, without the use of the plow.